What Happened to My Soap ?

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SWBAT identify and become fluent in key weathering vocabulary as students explore the meaning of erosion.

Big Idea

Using a bar of soap, students discover the meaning of erosion.

Math Connection: Measuring and Setting up our Lab.

15 minutes

Three Part Lesson Integrated Through A Day: This highly integrated lesson needs to be taught throughout the day in order to be most successful. You are able to tweek it to meet your needs, but remember that the soap needs to be soaked awhile in order to see the results of the water erosion. 

Materials: Bar of Ivory Soap cut into various size chunks, but not less than 2" pieces. Ivory is the softest soap and will respond to the water quickly. Metric Rulers. Interactive Science Notebook,What Happened to My Soap? Data Sheet, pencils and a timer. This lesson needs to be divided between math and science. Take the first measurements during math and then set the bars of soap in some warm water to soak.

Taking off right away! I needed to get our experiment up and running right away today since it requires some time for the water to soften the soap and some math. We began our lesson earlier in math class, as I taught them how to calculate area and volume. I approached my students today by simply saying, "Let's talk soap a minute. What do you know about a bar of soap? What have you observed about them over the years of bathing and showering?" I gave students a few minutes to answer and we discussed the aspects of bar soap as I held the bar of Ivory up.

In math class, I told them we would be using soap to discover some interesting things about weathering. I told them that we would be using some recently learned multiplication skills and some new measuring skills. I explained that it was important to first understand how to measure and understand the unit that we would be using. I wrote millimeters on the board and began by asking students to pluck a hair from their head and observe the width of their hair.  There were lots of "ows", but we kept moving! I explained that the linear metric unit for millimeter is that size. I explained that we would be using this unit to measure our soap and that we would be using what we had learned about multiplication and area models in math to understand how to find volume.

I wrote the word volume on the board. I modeled measuring volume using millimeters by measuring a tissue box, and writing the measurements on the whiteboard. I explained that volume was the term we use when we are talking about measuring how much matter takes up space in a 3 dimensional contained space. I explained that everything has volume, but does not always have length, width and height. I continued by saying that today we would only be measuring volume of something with length, width and height.

I picked up the tissue box and explained that a box of tissues holds a volume of tissues. I picked up the chunk of soap and explained that even though the bar of soap is not empty like a box or a cup, it has volume and we could measure it using multiplication.

I wrote the formula on the board, LxWxH, and explained that it would be noted in cubic mm. or mm3 for units today.  I related it back to the idea of exponents and square numbers so that they could connect their prior knowledge from recent lessons in math. Then, I multiplied the three two digit numbers, using area model to multiply. I explained that their numbers would be much more simple.

Explicit direction: We had grouped ourselves in threes prior to the lesson. These groups were given rulers and their chunk of soap. I explained that they needed to decide how to work as a team, remembering that each person needed to take turns measuring one side. I showed them explicitly the length, width and height, calling two students up to be a part of my example team, so there was no confusion. I drew a sketch of the bar of soap on the whiteboard, measured, recorded and noted each measurement on my drawing. I explained that the left side of their notebook needed a drawing like this. I then explained that the measurements needed to be noted in their Soap Data Sheet. This sheet needed to be glued into the right side of their notebook. I showed them how to multiply each measurement, using my example and reminding them of their recent math lesson on double digit multiplication.

 I asked that they begin their work and multiply it as a team using their area model method and then check accuracy with me after they were finished. They needed to enter their answer in their chart using the correct units of measurement. They were to check each other for accuracy.

Because each group worked at different paces, I roved around making sure they were measuring the correct aspects and setting up their models correctly. They were to sketch what they had done on the left side of their notebook and then glue in the chart in the right side. We set the soap in warm water to soak for a few hours and would return to it in the afternoon.

Observing the Change

10 minutes

The focus word, "erosion," was written on the whiteboard so that students could become familiar with the focus vocabulary word.  I planned on returning to it after sharing the experiment to see if students could connect that word to the lesson. This strategy drives the vocabulary meaning in another different direction and helps them be immersed in understanding it through possibly looking it up, (if their group had chosen it), preparing note cards, and then experiencing it from the investigation. It allows them to think, question and connect as teams of students, which supports their learning thoroughly.

After soaking for several hours, we returned to the lab to begin observations of erosion of the soap. I explained what needed to be done, reviewed the concepts of volume and area and showed them how to use the spray bottles. We planned on emptying three water bottles directly onto the soap by spraying, but they needed to choose how intense the stream would be first by playing with the stream. I told them that the stream needed to be consistent throughout the experiment.

I asked them what they needed to do next to see if they could reason what would be logical in finding our results. They responded by telling me that they needed to measure the soap again, note its changes and sketch in their notebook. I reminded them that they needed to calculate the volume again just as they had before noting any changes in the math. I told them I wanted them to think about what they were seeing and start to reason why they were seeing a change.

They began their work as I began roving around and checking their work. It was great fun watching them discover what the water had done to the soap! It was described by words like "gooey" and "slimy." They entered their data again and calculated area of the top and volume. They were careful to measure the same sides of the soap. Teams got their water bottles set up and they began taking turns spraying. The results varied depending upon the intensity of the spray. I coached one team to twist it so at least one water bottle sprayed a sharp stream so that the soap would be cut into.

During this activity, any difficulties the math should be addressed, but it still should not be the main focus. The main focus is the change in the soap they can see visually as they spray the water bottle.


Jigsawing the New Vocabulary

15 minutes

Language Arts Class: Earlier on this day...

To help with vocabulary speed, during language arts and word work time, I had students cut out their vocabulary words and glue them onto blank 3x5 cards. This prepared them for the next steps to be prepared for science prior to the lesson. We had pronounced the words together in class and said them three times to ensure proper pronunciation and recall.  During the morning word work, students were to look up the word and find the part of speech, labeling it just below the word. 

Jigsawing: This activity helps keep students engaged while one team mate is spraying the soap. In their groups of three, students chose three words do research and find meanings. They wrote their definition on the back of the note card and created a small drawing of an example of the word. Then, in these groups they focused on teaching one word to each other as they filled out their cards, discussed and drew a similar picture. We followed the Frayer Model Template, but used the note cards as our product instead of the template. If you prefer, skip the note card idea and simply use the templates. It works just as well, but is a paper resource instead of a handier note card. As the lessons progress, the same group meets each day to build their vocabulary understanding. I roved the classroom and helped them discover the meanings of each word. 

Students traded off the job of spraying the soap and went back and forth between the soap spray and the words. It was a perfect way of keeping students busy because the spraying takes time. I wanted to see three bottles emptied, but could see that they tired of the spraying quickly. So, I adjusted that to one bottle as I could see there would be results from spraying one bottle. 

As soon as the bottle was emptied, students returned to their soap and measured once again, entering the data in the chart.

Sharing the Observation

10 minutes

I asked students to share what they had found in their investigations today. Students raised hands and explained that they saw a change in the soap's size and volume. They shared different bits of data and talked about how it had changed. I asked them if there were any words in the word work they did earlier that would possibly explain what had happened?

We discussed how the intensity of the spray mattered since it was apparent that the team with the straight stream had cut into their soap. The softer sprays had less impact. The data on that soap remained unchanged. This observation allowed me to direct the conversation toward understanding that the intensity of the water would matter on how fast a rock would weather. They determined that the stronger the stream of water, faster erosion occurred. We all agreed however, that water erosion was a slow process. To connect it to engineering, I asked: "As a consumer or a person buying this soap, how would its fast shrinkage affect your desire to use this brand?" I explained that scientists, who are chemists, invent soaps and put them under a myriad of tests before they go to market. That soap is a type of technology.

As I wrapped up, I explained I wanted them to see a short movie clip that would help them understand and connect Wisconsin to what we had learned today about water and what it can do!

I assigned What Happened to My Soap? Question Sheet for homework. I told them to use their data charts and notebook observations to help with answering questions. 

Connecting the Word Erosion to Earth Science

5 minutes

 When all were finished with their observations, notes and drawings in their note books, I wanted to connect and build upon knowledge of erosion, so I chose to show this Bill Nye clip to 2:40. This movie up to that point would be just enough to get more inquiry bubbling in their brains!

To connect to CCSS standard that requires students to know about main ideas, I asked students what the main idea and key word that Bill Nye was trying to convey in this short clip. 

To move the concept of erosion closer to home, I asked them if there were any places in Wisconsin that looked a little like where Bill was hiking? I brought up the Smart Board and showed them photos of a Wisconsin Dells Postcard and Kyaking near Black Hawk Island.

Because this unit soon takes us to the Himalyas and a river in Nepal, I wanted to connect them to their own prior knowledge of their own state. Erosion is happening on the soft sandstone of the Dells every day. It is a great example of the quick eroding surfaces. This closing transitions them into the next lesson of our unit very well!